Diesel Cayenne and VW emission issue
09-18-2018 | 09:11 PM
#5867
RL Community Team
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From: The Woodlands, TX.
I'm leaning towards TCM tune being the primary culprit here, with engine tune exacerbating the effect.
Noticed something yesterday while driving. Hot day again, so the delay was pretty noticeable.
Rolled through a corner, perhaps a smidge lower than usual (maybe 15-16mph) onto a 50mph road and noticed that the CD had pre-selected 2nd gear. I rolled through the corner, tipped into the throttle, and the CD started to accelerate in a "normal" fashion (i.e. not lagged/delayed/broken) for literally about 1/2 second. It was definitely less than a full second. Then the CD *upshifted* to 3rd AND locked up the torque converter. I was stuck at ~1300rpm, 3rd gear, and maybe 20mph? Pushed the pedal all the way to the floor (but did not click into the kickdown button) and literally just kinda sat there, loping along. It was accelerating but it was as if I was giving it 5% throttle. No traffic coming behind me so I didn't panic, I was able to just observe. A solid 2s of that BS and I pushed the pedal into the kickdown button. THEN it downshifted BACK to 2nd and took off.
Why the F did the thing upshift to 3rd? And then give me TC lockup?
Noticed something yesterday while driving. Hot day again, so the delay was pretty noticeable.
Rolled through a corner, perhaps a smidge lower than usual (maybe 15-16mph) onto a 50mph road and noticed that the CD had pre-selected 2nd gear. I rolled through the corner, tipped into the throttle, and the CD started to accelerate in a "normal" fashion (i.e. not lagged/delayed/broken) for literally about 1/2 second. It was definitely less than a full second. Then the CD *upshifted* to 3rd AND locked up the torque converter. I was stuck at ~1300rpm, 3rd gear, and maybe 20mph? Pushed the pedal all the way to the floor (but did not click into the kickdown button) and literally just kinda sat there, loping along. It was accelerating but it was as if I was giving it 5% throttle. No traffic coming behind me so I didn't panic, I was able to just observe. A solid 2s of that BS and I pushed the pedal into the kickdown button. THEN it downshifted BACK to 2nd and took off.
Why the F did the thing upshift to 3rd? And then give me TC lockup?
09-19-2018 | 12:25 PM
#5868
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Joined: May 2006
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Here's a VW Service Training document on the 3.0 TDI that describes the swirl flaps. I assume everything applies to the Cayenne CD as well.
http://www.volkspage.net/technik/ssp/ssp/SSP_350.pdf
http://www.volkspage.net/technik/ssp/ssp/SSP_350.pdf
09-19-2018 | 04:28 PM
#5870
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Joined: Dec 2016
Posts: 85
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From: B.C Canada
Sorry,
I should of described what I mean a little more clearly, the CD has a Butterfly Valve ( Flap ) in line with the intercooler sys.
This regulates ambient air intake at different points of operation.
As for the Touareg and Audi applications, I'm not sure.
One thing we do have; and that's all aluminum intercoolers and not partial plastic pieces.
I should of described what I mean a little more clearly, the CD has a Butterfly Valve ( Flap ) in line with the intercooler sys.
This regulates ambient air intake at different points of operation.
As for the Touareg and Audi applications, I'm not sure.
One thing we do have; and that's all aluminum intercoolers and not partial plastic pieces.
09-19-2018 | 06:21 PM
#5871
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But the sudden UPSHIFT and IMMEDIATE TC lockup was unusual. The 2nd gear acceleration, the motor revved up like the TC was't locked, and it started to accelerate... then suddenly, upshift + lockup and bog...
09-20-2018 | 02:16 PM
#5872
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Joined: Jan 2014
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From: Fruita, CO
Obviously I've been giving this a lot of thought.
I wonder if it might be as simple as swapping out the computers in the car? Computers glitch... maybe one or both (DME, TCU) have a glitch somewhere that causes the apparent disconnect between requesting power (stepping on the accelerator) and delivering power? Fresh computers, fresh software...no lag/surge power cycle?
Simple from my perspective, anyway. Probably not so simple (or inexpensive) from theirs.
I wonder if it might be as simple as swapping out the computers in the car? Computers glitch... maybe one or both (DME, TCU) have a glitch somewhere that causes the apparent disconnect between requesting power (stepping on the accelerator) and delivering power? Fresh computers, fresh software...no lag/surge power cycle?
Simple from my perspective, anyway. Probably not so simple (or inexpensive) from theirs.
09-22-2018 | 04:17 PM
#5874
Racer
Joined: Jul 2006
Posts: 485
Likes: 15
From: Treasure Coast
Obviously I've been giving this a lot of thought.
I wonder if it might be as simple as swapping out the computers in the car? Computers glitch... maybe one or both (DME, TCU) have a glitch somewhere that causes the apparent disconnect between requesting power (stepping on the accelerator) and delivering power? Fresh computers, fresh software...no lag/surge power cycle?
Simple from my perspective, anyway. Probably not so simple (or inexpensive) from theirs.
I wonder if it might be as simple as swapping out the computers in the car? Computers glitch... maybe one or both (DME, TCU) have a glitch somewhere that causes the apparent disconnect between requesting power (stepping on the accelerator) and delivering power? Fresh computers, fresh software...no lag/surge power cycle?
Simple from my perspective, anyway. Probably not so simple (or inexpensive) from theirs.
_____________
2014 991 TT
2018 95B S
09-22-2018 | 08:14 PM
#5875
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Joined: Oct 2006
Posts: 9,615
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From: CT
Originally Posted by TAch Miami
Has anyone reflashed with original programming? Maybe an unfixed CD could be flashed to a Cobb access port and then reloaded into yours.
_____________
2014 991 TT
2018 95B S
_____________
2014 991 TT
2018 95B S
09-23-2018 | 04:04 AM
#5876
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From: Fruita, CO
09-23-2018 | 11:07 AM
#5877
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From: The Woodlands, TX.
09-23-2018 | 06:40 PM
#5878
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Joined: Sep 2009
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I’ve been emailing a bit with the open flash guys about the issues with the fix software. I had originally asked them about reverting to the prior software and they had this to say about that:
So basically if there are no improvements made to the mapping by Porsche and us owners decide the behavior is problematic enough to go with an aftermarket solution it sounds like tuning the fixed map might be easier/safer than trying to revert to pre-fix software at least when it comes to the ECU and this tuning platform.
Were still not in a position to offer this type of support with the OFT - most notably because the device will only reprogram matching software when compared to whats already in the ECU.
To perform some software upgrades (especially downgrades) can be dangerous and result in a 'bricked' unrecoverable ECU
To perform some software upgrades (especially downgrades) can be dangerous and result in a 'bricked' unrecoverable ECU
09-24-2018 | 01:10 AM
#5879
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From: Fruita, CO
Another interesting data point. I've been driving my wife's '14 while she was out of town. I've previously mentioned I was worried it was starting to show some lag symptoms, too. But now that it's cooled down, it's driving like it was never flashed (except for the engine braking - that's unmistakably gone).
So while my '15 doesn't see any impact based on temp - it sucks in all temps! - the '14 is apparently "normal", per post fix operations and the observations you've all reported.
So while my '15 doesn't see any impact based on temp - it sucks in all temps! - the '14 is apparently "normal", per post fix operations and the observations you've all reported.
